What Causes Skin Discoloration?

There are many potential causes of skin discoloration, ranging from minor problems to more serious medical conditions. These may include:

• birthmarks, which are discolored skin spots that may be present at or shortly after birth
• pigmentation disorders, such as melasma, albinism, and vitiligo
• medical conditions, such as rosacea, psoriasis, and Graves‘ disease
• infections from harmful bacteria, viruses, or fungi
• allergies, which may lead to hives or eczema rashes
• skin cancer, which develops from damaged skin cells that become malignant (cancerous)
• other causes, such as burns and medication side effects

Let’s look at these potential causes of skin discoloration in more detail.

Birthmarks

Birthmarks are discolored skin spots that can develop at birth or soon after birth. They are typically harmless and don’t require treatment unless they become bothersome or painful.

Some common types of birthmarks include:

• Moles. Moles can appear on the skin at birth. They can range in color from tan, brown, or black to red, purple, and blue. Some moles may even be the same color as your skin. Most moles aren’t a cause for concern, but any changes in the size or shape of a mole can signal trouble and should be checked by a healthcare professional.
• Dermal melanocytosis (formerly Mongolian blue spots). Bluish patches can appear on the backs of babies and young children, usually in those of Asian descent. These blue spots are harmless and often fade over time.
• Port-wine marks. Port-wine marks are flat patches that appear pink or red on lighter skin tones and dark purple or violet-red on darker skin tones. They are caused by swollen blood vessels under the skin.
• Salmon patches. Salmon, red, or pink-colored patches that may develop on a baby’s face or neck. This birthmark tends to go away on its own by ages 1 to 3.
• Strawberry nevus (hemangioma). A red birthmark that’s common in young children and infants. This birthmark usually fades by age 10.
• Deep hemangioma. This type of birthmark also tends to disappear by age 10. It appears as a purple- or blue-tinted lump under the skin that may require treatment if it’s painful or breaks open and bleeds.
• Hypopigmented macule. A spot of skin lighter than the rest of your body and tends to go away over time.
• Café au lait spots. Spots of skin that are much darker than the rest of the body. Unlike a hypopigmented macule, this type of birthmark remains for life.

Pigmentation disorders

Pigmentation disorders can cause changes in your skin that are either lighter (hypopigmentation) or darker (hyperpigmentation) than your natural skin tone. While usually harmless, more extensive pigmentation changes may lead someone to get aesthetic treatments.

Common pigmentation disorders include:

• Vitiligo. This chronic (long-term) condition causes large patches of hypopigmentation on your skin. While vitiligo can develop at any age, it typically begins before age 20.
• Albinism. Albinism is an inherited condition that leads to the development of extremely light skin, eyes, and hair due to a lack of melanin.
• Melasma. Nicknamed “the mask of pregnancy” due to the involvement of progesterone and estrogen, melasma is a type of hyperpigmentation that causes darker spots of skin on the face and abdomen. It usually fades and gets lighter once you stop taking birth control pills or after pregnancy. Certain amounts of sun exposure can cause it to return.
• Age or “liver“ spots (lentigo). These are common hyperpigmentation spots caused by sun damage. Age spots can develop anywhere on the body, but they tend to affect sun-exposed areas, such as your hands, chest, and face.

Medical conditions

The immune system normally works to keep the body healthy by fighting off harmful agents that can cause infection and disease.

In people with autoimmune diseases, however, the immune system confuses healthy cells for something foreign and attacks them by mistake. This triggers inflammation throughout the body, resulting in various symptoms, including swelling and redness.

Some autoimmune diseases and other medical conditions that may lead to symptoms of skin discoloration include:

• Psoriasis. Psoriasis is a chronic skin condition characterized by itchy patches of red to silvery scales that are caused by an increase in skin cell turnover.
• Rosacea. This condition may cause skin flushing and redness. Some types of rosacea may also cause acne pustules, ocular (eye) symptoms, and thickened skin.
• Lupus. Lupus can affect the skin and other areas in your body, including your joints and major organs.
• Stasis ulcer. A leg ulcer often coincides with varicose veins and venous insufficiency, leading to redness, swelling, and pain.
• Graves’ disease. A type of thyroid disease that causes your body to produce too many thyroid hormones. Related skin symptoms may include areas of rough, thickened, red skin.
• Addison’s disease. This adrenal insufficiency condition may cause areas of hyperpigmentation in the skin. You may also be at an increased risk of developing vitiligo.
• Scleroderma. Scleroderma is a rare autoimmune disorder that may cause patches of thick, discolored skin, as well as problems with connective tissues.

Infections

Various infections can cause changes in skin color in the affected area.

Infections that may lead to discolored skin include:

• Bacterial infections. Cuts, scrapes, and other wounds may become infected when bacteria enter, resulting in skin texture changes. The surrounding area may also turn red or white, and the wound may have discharge. Topical or oral antibiotics may be prescribed for these types of skin infections.
• Fungal infections. Fungal infections, such as ringworm, tinea versicolor, and candida, can also trigger discolored skin patches on various body parts. Topical or oral fungal treatments may be used for these conditions.
• Viral infections. Viral infections, such as shingles, cold sores, and warts, may lead to red, purple, or brown bumps or sores. Antiviral treatments may be used for certain types of infections.

Rashes and allergies

Allergic reactions to foods, plants, or irritants can also result in discolored skin patches in various body areas. These changes may appear as rashes or raised bumps that itch or burn and can occur in the following:

• Eczema (atopic dermatitis). Like certain autoimmune diseases, eczema triggers an immune reaction that attacks the skin. The condition can cause scaly patches and red bumps that ooze or crust over.
• Contact dermatitis. Contact dermatitis is another type of allergic skin rash that can develop when you come into contact with fragrances, skin care products, metals, or clothing that irritates your skin. Contact dermatitis rashes are often itchy and sometimes even painful.
• Hives (urticaria). These raised, itchy bumps on the skin resulting from inflammation from your body releasing histamine (a compound involved in immune responses) in response to an allergen. While usually acute, some cases of hives can be chronic, lasting for months or even years.

Skin cancer

Cancer can change the skin’s color or texture. Skin cancer may occur when the genetic material in skin cells becomes damaged, often from long-term sun damage or exposure to chemicals. The damage may cause the cells to grow out of control and form a mass of cancer cells.

There are several types of skin cancer, all of which require treatment:

• Actinic keratosis. A precancerous skin condition characterized by scaly, crusty spots on the hands, arms, or face. These spots are typically brown, gray, or pink. The affected area may itch or burn.
• Basal cell carcinoma. The most common form of skin cancer, basal cell carcinoma, affects the top layer of the skin. It most often appears in sun-exposed areas. In the early stages, it produces lesions that bleed. The associated bumps may be discolored, shiny, pearly, or scar-like. They can look like open sores and often have slightly higher edges with an indentation in the middle.
• Squamous cell carcinoma. A type of skin cancer that begins in the squamous cells. These cells make up the outermost layer of skin. This condition causes scaly, red patches and raised sores, which are also often seen on sun-exposed areas of the skin.
• Melanoma. This is the least common but most serious form of skin cancer. Melanoma begins as an atypical mole. Cancerous moles are often asymmetrical, multicolored, and large. They can appear anywhere on the body, but they usually first appear on the chest or back in people assigned male at birth and on the legs in people assigned female at birth.

Most discolored skin patches aren’t caused by skin cancer. However, you should ask a healthcare professional to examine misshapen moles or other rapidly changing skin lesions.

Other causes of skin discoloration

Other conditions and medical treatments that can cause skin discoloration include:

• Bleeding into the skin. This happens when blood vessels burst due to injury, bruising, or an allergic reaction.
• Radiation therapy. Radiation therapy is a cancer treatment that can cause the skin to blister, itch, and peel.
• Spider veins. Damaged veins can appear as clusters of red, blue, or purple lines underneath your skin, particularly in your legs.
• Hormonal changes. Hormonal changes may cause the development of melasma hyperpigmentation.
• Thermal injuries. Skin discoloration can occur after healing from burns associated with frostbite, sunburn, fire, and electrical injuries.
• Toxic exposures. Chronic application or ingestion of silver compounds (argyria) and heavy metals can lead to the deposition of metallic compounds in the skin and/or stimulate excess melanin production.
• Medication side effects. Drug-induced hyperpigmentation may occur in some people taking antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), and other drugs.

At your appointment, your doctor will first take a look at areas of skin discoloration and ask you about any changes you’ve noticed. They will also ask about other symptoms you may be experiencing.

Depending on your doctor’s findings during the physical exam, they may order further diagnostic testing to determine the cause of skin discoloration. While the exact tests may vary with each potential cause of discolored skin, the options may include:

• blood tests to check for conditions that may cause changes in skin color
• a Wood’s lamp examination to identify possible fungal or bacterial infections
• a skin biopsy to examine a small sample of the affected skin under a microscope for the presence of abnormal cells

Treatment for discolored skin patches depends on the underlying cause. If a healthcare professional finds an underlying health condition, they will attempt to treat it first.

Any active infection must be treated with the appropriate class of drugs. For example, antibiotics can treat bacterial infections, while antifungal medications treat fungal infections.

If you seek treatment for cosmetic reasons, a dermatologist may recommend over-the-counter or prescription topical treatments to reduce signs of skin discoloration. Professional treatments, such as chemical peels or microdermabrasion, may also be used to help reduce hyperpigmentation, but these aren’t usually covered by insurance.

It’s important to ask your doctor before trying topical treatments or home remedies that supposedly treat skin discoloration. You should always get a correct diagnosis first.

Can skin cancer cause skin discoloration?

Yes, skin cancer can cause skin discoloration, often appearing as changes in the color or size of moles or the emergence of new pigmented spots.

How do you treat patchy, discolored skin?

Patchy, discolored skin may be treated with topical medications, laser therapy, chemical peels, or microdermabrasion. Your care plan and expected results ultimately depend on the underlying cause.

How do you know if discoloration is cancerous?

A dermatologist can determine if skin discoloration is cancerous through a thorough examination, possibly followed by a biopsy for confirmation.

What are the seven warning signs of skin cancer?

The seven warning signs of skin cancer are changes in a mole’s size, shape, or color; irregular borders; asymmetry; itching, tenderness, or pain; oozing, bleeding, or scaliness; and developing a new spot.

What does stage 1 melanoma look like?

Stage 1 melanoma typically appears as a mole or pigmented spot with a distinct border and even color, usually smaller than 1 millimeter in thickness.

While many cases of skin discoloration are harmless, any unusual changes in your skin can be concerning. Some causes of discolored skin patches are minor conditions that only need simple treatments. Other causes may be more severe and require ongoing treatment.

It’s important to speak with a doctor about any skin changes that are unusual or bothersome, especially if you notice sudden symptoms or rapid changes in your skin. These could be an indication of a more serious condition.

Your doctor will diagnose the cause of your discolored skin and recommend treatments as appropriate. If skin discoloration is linked to an underlying medical condition, remember that skin symptoms may not disappear until the medical condition is first addressed.